Automatic firearm



Dec. 23, 1924. 1,520,671

H. RoslER Y AUTOMATIC Hamm Filed Dec, s, 1925 2 ,J y l atto/ama,

Patented Dec. 23, 1924.

UNITED STATES HENRY ROSTER, OF LOWELL, MASSACHUSETTS.

AUTOMATIC FIREAR-M.

Application filed December To all iti/0m t may concern.'

Be it known that I, HENRY Rosina, a citizen of the United States, residing at Lowell, in the county of Middlesex and State of Massachusetts, have made a certain new and useful Invention in Automatic Firearms, of' which the following is a specitication.

'The invention has relation to automatic firearms, having for its object the provision of simple and etiicient operating mechanism for the same. Other objects and advantages will hereinafter appear.

The invention consists in the novel construction and combinations of parts, as set forth in the appended claims.

In the accompanying drawings, illustrating a preferred form of the invention, Figure 1 is a side view of the invention; Figure 2 is a central longitudinal section of the same, with the parts .in normal position ready for tiring; Figure 3 is a similar fragmentary View, with the parts in position after tiring has taken place; Figure 4 is a similar view with the parts in the position taken after the recoil has taken place but before the breech block has been returned to normal position. In these drawings the numeral i designates a sliding breech block, held normally against the barrel 2 by a recoil spring 3 and having mounted therein a tiring pin a, held in rearward position by a spring ii. In rear of and below the barrel is located a removable magazine (i, having a spring follower' 7 and provided with side retaining iianges 8 at its top margin. rlhe ejector is shown at 9. All these parts operate in the well known manner, in cooperation with the mechanism of the lock, to utilize the recoil in automatic tiring.

The lock is located in rear of the magazine and comprises a hammer 10, a locking cam 11 and a trigger 12 having a rearward pivoted arm 13. The hammer is pivoted at 111 and includes a striking face 1.5 having a cam extension, a locking tooth 1G and a nose 1i. Spring 1T* tends to throw the striking face of the hammer toward iiring-pin 4, this tendency being normally resisted by engagement of locking tooth 16 with a tooth 18 of locking cam 11. Cam 11 is pivoted at 19 and provided with a face 20 designed to lie normally in contact with the rear end of trigger arm 13. Spring 21 presses cam 11 toward this normal position. The trigger is pivoted at 22 and has a rear shoulder 23, arm 13 being pivotally mounted thereon at 3, 1923. serial No. 678,302.

24e, below pivot 22. A spring 25 lies between arm 13 and shoulder 23 Vand acts to hold shoulders 26 and 27 of the trigger and arm normally out of contact. A safety lock pin 28 is adapted for sliding operation .into and out of contact with the shoulder 23, the exterior portion of said pin projecting in rear of the trigger guard, where it is not liable to be accidentally displaced.

The operation of the parts comprising the lock is as follows:

The trigger 12 being pressed, arm 13 thereof will trip the locking` cam 11 and thus release hammer 10, which will be brought againstA the firing pin L1 by spring 17X. In this movement nose 8 of the hammer will depress trigger arm 19, against the tension of its spring 9, bringing shoulder 27 against shoulder and throwing the trigger' forward into n :rmal position, against the finger pressure, thus allowing the locking cam 11 to resume its original position, under the iniiueuce of spring 2 The cartridge having been e.\:ploded. the recoil carries the breech block l backward against the hammer, camming the latter over to cocked position, in which ii" is relocked by cam 11. and arm 13, releaseiV by the hammer, will rise to its irst position, under the iniiuence of spring all these movements taking place before the 'muscmz reaction draws the trigger back to iring position. Parts 10, 11, 12 and 13 being now in their lirst position, and the linger pressure becoming again effective, the iammer will again be tripped, recoil spring 3 having meanwhile returned breech block 1 to for ia 'd position.

The automatic return of the trigger to forward position is of service in signaling the completion of each shot.. and in. initiating the release of the trigger at theproper moment when it is desired to cease liring.

I claim:

In. automatic firearms, a sliding breech block carrying a firing pin, a locking device, a hammer normally restrained by said device, and trigger mechanism including a member normally lying in. contact with said hammer and with said locking device and operable to release the hammer from said device, said hammer adapted when released to throw said member out of contact with the locking device.

In testimony whereof I aix my signature.

HENRY ROSTER, 

